I'm not sure you're comparing apples to apples, but please correct me if I'm wrong. The Procal literature advertises gains of 50 HP and 106 foot pounds of torque to 455 HP and 536 Torque, but that seems to be at the crank, not the wheels since stock is 405 HP and 430 torque. Aftermarket tuners...
But I personally would NEVER use anything other than Stock or Pro Cal for reliability unless I had a built bottom end (aftermarket forged Mahle Pistons, Rods, big turbos, higher flow injectors etc.) and a built race spec 10R60. On a factory engine and transmission, it's factory cal's, be it Ford...
That's my path too. My Ford Procal arrives today and if I'm satisfied with it, fine. If not I'll order the Accessport and get Goosetuned and never have to worry about a warranty claim. Just flash back to stock. The dealer will never know since I have the Procal too.
When my RR is in sport mode, it downshifts aggressively as I stop. I haven't looked at my tach, but the rpms certainly jump. Is there any chance that is what you feel?